Multi-speed transmission in planetary design

ABSTRACT

A multi-speed transmission in planetary design for a vehicle with a housing includes a first shaft provided as a drive and a second shaft provided as an output that is arranged axially parallel to the drive. Three planetary gear sets and additional shafts along with six shifting elements are provided, through which the actuation of several gears are realized. Machine elements are provided for the transfer of torque between the drive and the output. The first shaft is connectable, as a drive, to the sun gear of the third planetary gear set, to the planetary gear carrier of the second planetary gear set, to the planetary gear carrier of the third planetary gear set, and is connectable or connected to the sun gear of the first planetary gear set. The second shaft is connected or connectable, as a drive, to the first machine element and to the second machine element.

FIELD OF THE INVENTION

The present invention relates to a multi-speed transmission in planetarydesign for a vehicle.

BACKGROUND

As an example, publication DE 10 2007 014 150 A1 discloses aload-shiftable multi-speed transmission. With the multi-speedtransmission, the drive shaft is firmly connected through a torsionalvibration damper to a first shaft of a first shaft train. A second shafttrain arranged parallel to this includes, among other things, the twooutput shafts designated as shafts. The two shaft trains are connectedto each other through three spur gear stages. A first three-shaftplanetary gear stage is located on the first shaft train. A secondplanetary gear stage and a third planetary gear stage are located on thesecond shaft train. Thus, the multi-speed transmission comprises tenshafts that are connected to each other through three spur gear stagesand three planetary gear stages. For shifting the eight forward gearsand one reverse gear, five shifting elements are necessary. The providedshifting elements are hydraulically operated.

In order to reduce hydraulic losses, the shifting elements are to bearranged in a manner that is easily accessible from the outside.However, with a front-transverse installation of the transmission in avehicle, only a limited axial installation space is available.

SUMMARY OF THE INVENTION

The present invention is subject to a task of providing a multi-speedtransmission with the highest possible number of gears and an easyaccessibility of the shifting elements, with, at the same time, a goodgearing efficiency and a need for axial installation space that is aslow as possible. Additional objects and advantages of the invention willbe set forth in part in the following description, or may be obviousfrom the description, or may be learned through practice of theinvention.

This task is solved by the characteristics of the embodiments describedand enabled herein.

Accordingly, a load-shiftable multi-speed transmission in planetarydesign, or a multiple-gear planetary transmission for a vehicle with ahousing, is proposed, whereas the drive or the drive shaft, as the casemay be, and the output or the output shaft, as the case may be, arearranged axially parallel to each other for a preferred front-transverseinstallation. The multi-speed transmission in accordance with theinvention comprises only nine shafts, three planetary gear sets and onlysix shifting elements, in order to realize at least nine forward gearsand one reverse gear. In addition, for the coupling of the drive and theoutput, it is preferable that only two machine elements are provided.

Given the fact that the first shaft, as a drive, is detachably connectedor connectable to the sun gear of the third planetary gear set, to theplanetary gear carrier of the second planetary gear set, to theplanetary gear carrier of the third planetary gear set, and isconnectable or connected to the sun gear of the first planetary gearset, and that the second shaft, as an output, is connected, or isdetachably connected or connectable, to the first machine element and tothe second machine element, a multi-speed transmission in accordancewith the invention that enables an actuation of the shifting elementsthat improves the degree of efficiency and is thus in line with demandarises. The advantageously low number of transmission elements of themulti-speed transmission for a front-transverse design has itstransmission elements nested with each other in such a manner that anarrangement that particularly saves axial installation space is enabled.In addition to the improved degree of efficiency, low component stressesand low construction costs arise.

The easy accessibility of the shifting elements may be realized, amongother things, on the one hand through the use of brakes as shiftingelements and, on the other hand, through the use of clutches as shiftingelements, which are preferentially positioned at outside shafts,preferably at the drive and at the output, with the multi-stagetransmission in accordance with the invention. Due to the lowconstruction costs, in an advantageous manner, low production costs anda low weight of the multi-speed transmission in accordance with theinvention arise.

Within the framework of a possible embodiment of the invention, it canbe provided that, as a machine element for the coupling or for thetransfer of torque between the drive and the output, at least one spurgear stage or the like, which realizes the transmission ratio for theoutput differential, is used. Preferably, only two machine elements orspur gear stages are provided. However, other machine elements for thetransmission of torque power, such as chains, belts or the like, may beused.

Viewed in an axial direction, the planetary gear sets are arranged inthe order of first planetary gear set, second planetary gear set andthird planetary gear set, whereas it is preferable that at least onepositive planetary gear set and at least one negative planetary gear setare provided. However, at spots where the binding ability allows it,individual or several negative planetary gear sets may be converted intopositive planetary gear sets or vice versa, if, at the same time, thebar connection or planetary gear carrier connection and the ring gearconnection are exchanged, and the amount of the stationary transmissionratio is increased by the value of 1. As is well-known, a negativeplanetary gear set features, at the planetary gear carrier, rotatablymounted planetary gears, which mesh with the sun gear and the ring gearof such planetary gear set, such that, with a planetary gear carrierthat is held down and a rotating sun gear, the ring gear rotates in adirection opposite to the direction of rotation of the sun gear. As iswell-known, a positive planetary gear set features, at its planetarygear carrier, inner and outer planetary gears that are rotatably mountedand are in a tooth meshing with each other, whereas the sun gear of suchplanetary gear set meshes with the inner planetary gears, and the ringgear of such planetary gear set meshes with the outer planetary gears,such that, with a planetary gear carrier that is held down and arotating sun gear, the ring gear rotates in the same direction as thedirection of rotation of the sun gear.

With the multi-speed transmission in accordance with the invention, ahydrodynamic torque converter or a hydrodynamic clutch can be used asthe start-up element. It is also conceivable that an additional start-upclutch or an integrated start-up clutch or a start-up brake are used.Furthermore, it is possible that an electric machine or any other powersource is arranged at at least one of the shafts. Moreover, at at leastone of the shafts, a freewheel is arranged for the housing or foranother shaft.

Preferably, with the multi-speed transmission in accordance with theinvention, nine forward gears and at least one reverse gear can beshifted by means of the provided shifting elements. However, it isconceivable that additional shifting combinations are made possible bycombining other shifting elements.

Under the term “shifting element,” a shiftable connection between twoelements of the transmission is understood, whereas the torque to betransferred between such two elements is transferred by means of theforce closure or frictional closure or by means of the form closure. Ifboth elements of the shiftable connection are designed to rotate, theshifting element is referred to as a clutch, and if only one of the twoelements of the shiftable connection rotates, the shifting element isreferred to as a brake. Moreover, the geometric position and/or order ofthe individual shifting elements can be freely selected, as long as thebinding ability of the elements allows this. In this manner, individualelements may be arbitrarily moved into any position. In addition, to theextent permitted by the external shape, several gear sets can bearranged radially above one another, thus in a nested manner.

Embodiments of a force-fitting shifting element include multi-diskclutches or brakes, band brakes, cone clutches or brakes,electromagnetic clutches, magnetic powder clutches andelectro-rheological clutches. Embodiments of a positive-locking shiftingelement include claw clutches or brakes and tooth clutches.

Thus, in general, both frictional-locking and positive-locking shiftingelements may be used as shifting elements. Preferably, given theircharacteristics, in particular the fifth shifting element designed as abrake and the third shifting element designed as a clutch can bedesigned as claw shifting elements, by which significant consumptionadvantages can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the present invention is explained in more detailbased on the drawing. The following is shown:

FIG. 1 is a schematic view of a design variant of a multi-speedtransmission in accordance with the invention;

FIG. 2 is a schematic view of a design variant of the multi-speedtransmission with an alternative arrangement position of the thirdshifting element;

FIG. 3 is a schematic view of a design variant of the multi-speedtransmission with an alternative arrangement position of the thirdshifting element;

FIG. 4 is a schematic view of a design variant of the multi-speedtransmission with an alternative arrangement position of the thirdshifting element;

FIG. 5 is a schematic view of a design variant of the multi-speedtransmission with an alternative arrangement position of the thirdshifting element;

FIG. 6 is a schematic view of a design variant of the multi-speedtransmission with an alternative arrangement position of the thirdshifting element; and

FIG. 7 is a shifting diagram for the various design variants of themulti-speed transmission.

DETAILED DESCRIPTION

Reference will now be made to embodiments of the invention, one or moreexamples of which are shown in the drawings. Each embodiment is providedby way of explanation of the invention, and not as a limitation of theinvention. For example features illustrated or described as part of oneembodiment can be combined with another embodiment to yield stillanother embodiment. It is intended that the present invention includethese and other modifications and variations to the embodimentsdescribed herein.

Each of FIGS. 1 to 6 shows an example of a design variant of themulti-speed transmission in planetary design in accordance with theinvention, for example as an automatic gearbox or automatictransmission, for a vehicle, for which varying arrangement positions ofthe third shifting element designed as a clutch are shown.

Regardless of the particular design variants, the multi-speedtransmission comprises a merely schematically indicated housing 11, witha first shaft 1 as a drive An and a second shaft 2 as an output Ab thatis arranged in a manner axially parallel to the drive, along with sevenadditional shafts 3, 4, 5, 6, 7, 8, 9. Furthermore, a first planetarygear set RS1, a second planetary gear set RS2 and a third planetary gearset RS3 are provided, whereas each of the first planetary gear set RS1and the third planetary gear set RS3 is preferably designed as anegative planetary gear set, and the second planetary gear set RS2 isdesigned as a positive planetary gear set. For shifting several gears, afirst shifting element K1 designed as a clutch, a second shiftingelement K2 designed as a clutch, a third shifting element K3 designed asa clutch, a fourth shifting element K4 designed as a clutch, a fifthshifting element B1 designed as a brake, and a sixth shifting element B2designed as a brake are provided.

In relation to the design variant in accordance with FIG. 1, FIGS. 2 to6 show transmission variants with the same effect, with which thearrangement position of the third shifting element K3 designed as aclutch varies, The different design variants do not functionally differfrom the design variants in accordance with FIG. 1 with respect todegree of efficiency, grading, etc. The shifting matrix shown in FIG. 7remains identical for all design variants.

With a pair of spur gears (or spur gear stage ST1, ST2), which isconnected through a shifting element to a shaft (idler gear), it ispossible that the shifting element is allocated to the main shaft on thedrive side (shaft 1) or the immediate shaft on the output side (shaft2). One example of this is the arrangement positions of the thirdshifting element K3 designed as a clutch with the design variants inaccordance with FIGS. 5 and 6. It is also easily possible that thefourth shifting element K4 designed as a clutch is positioned on themain shaft on the drive side.

For the coupling or for the transfer of torque between the drive An andthe output Ab, two arbitrary machine elements are preferably provided;with the design variants, these are designed, for example, as a firstspur gear stage ST1 and a second spur gear stage ST2. With the designvariants in accordance with FIGS. 1 to 4, the first spur gear stage ST1comprises a fixed gear 12, which is connected to the sixth shaft 6, anda fixed gear 13 in a meshing with this, which is connected to the secondshaft 2. The second spur gear stage ST2 comprises a fixed gear 14, whichis connected to the seventh shaft 7, and an idler gear 15 in a meshingwith this, which is connected through the ninth shaft 9 and through thefourth shifting element K4 designed as a clutch to the second shaft 2.With the design variant in accordance with FIG. 5, an idler gear 12Ainstead of the fixed gear 12 is provided upon the first spur gear stageST1; such idler gear is connected through the sixth shaft 6 to the thirdshifting element K3 designed as a clutch.

With the design variant in accordance with FIG. 6, the first spur gearstage ST1 comprises the fixed gear 12, which is in a mesh with an idlergear 13A. The idler gear 13A is connected through the fifth shaft 5through the third shifting element K3 designed as a clutch to the secondshaft 2. The second spur gear stage ST2 comprises the fixed gear 14,which is connected to the seventh shaft 7. The fixed gear 14 is in ameshing with the idler gear 15. The idler gear 15 is connected throughthe ninth shaft 9 and through the fourth shifting element K4 designed asa clutch to the second shaft 2.

With respect to the connection options between the provided shafts 1, 2,3, 4, 5, 6, 7, 8, 9, the provided three planetary gear sets RS1, RS2,RS3, the provided housing 11 and the provided shifting elements K1, K2,K3, K4, B1, B2 along with the provided spur gear stages ST1, ST2, withthe term “connectable, it is to be understood that the describedelements are detachable (for example, connected by a shifting element),such that the connection is locked with an activated shifting elementand open with a non-activated shifting element. The detachableconnection may be realized through, in addition to the shifting element,an additional element such as a shaft or the like. With the term“connected,” it is to be understood that the described elements areconnected to each other in a manner that is virtually fixed, thus notdetachable. A direct or indirect fixed connection (for example, throughadditional elements) may be realized.

In accordance with the invention, it is provided with the multi-speedtransmission that the first shaft 1 is detachably connected orconnectable, as drive An, to the sun gear SR3 of the third planetarygear set RS3. Furthermore, the first shaft 1 is connectable to theplanetary gear carrier PT2 of the second planetary gear set RS2 and tothe planetary gear carrier PT3 of the third planetary gear set RS3.Moreover, the first shaft 1 is connectable or connected to the sun gearSR1 of the first planetary gear set RS1. Depending on the designvariant, the second shaft 2 is connected or connectable, as output Ab,to the first machine element or the first spur gear stage ST1, as thecase may be, and the second machine element or the second spur gearstage ST2, as the case may be.

Regardless of the design variants, the first shaft 1 is connectablethrough the first shifting element K1 designed as a clutch and throughthe third shaft 3 to the sun gear SR3 of the third planetary gear setRS3, whereas the sun gear SR3 of the third planetary gear set RS3 isconnectable through the third shaft 3 and through the sixth shiftingelement B2 designed as brake to the housing 11.

With the design variants in accordance with FIGS. 1 and 2 and 4 to 6,the first shaft 1 is connectable through the second shifting element K2designed as a clutch and through the fourth shaft 4 to the planetarygear carrier PT2 of the second planetary gear set RS2 and to theplanetary gear carrier PT3 of the third planetary gear set RS3. With thedesign variant in accordance with FIG. 3, the first shaft is connectablethrough the second shifting element K2 designed as a clutch and throughthe fourth shaft, and through the third shifting element K3 designed asa clutch and through the fifth shaft 5, to the planetary gear carrierPT2 of the second planetary gear set RS2. The planetary gear carrier PT3of the third planetary gear set RS3 and the planetary gear carrier PT2of the second planetary gear set RS2 either are connected through thefourth shaft 4 or, according to the design variant in accordance withFIG. 3, are connectable to each other through the third shifting elementK3 designed as a clutch and the fifth shaft 5.

Regardless of the design variants, the planetary gear carrier PT3 of thethird planetary gear set RS3 and the planetary gear carrier PT2 of thesecond planetary gear set RS2 are connectable through the fourth shaft 4and through the fifth shifting element B1 designed as a brake to thehousing 11.

With the design variant in accordance with FIG. 1, the first shaft 1 isconnectable through the third shifting element K3 designed as a clutchand through the fifth shaft 5 to the sun gear SR1 of the first planetarygear set RS1. With the additional design variants in accordance withFIGS. 2 to 6, the first shaft 1 is connected to the sun gear SR1 of thefirst planetary gear set RS1, almost directly without a shiftingelement.

With the design variants in accordance with FIGS. 1 to 5, the secondshaft 2 is connected to the fixed gear 13 of the first spur gear stageST1. Furthermore, the second shaft 2 is connectable through the fourthshifting element K4 designed as a clutch and through the ninth shaft tothe idler gear 15 of the second spur gear stage ST2. With the designvariant in accordance with FIG. 6, the second shaft 2 is connectablethrough the third shifting element K3 designed as a clutch and throughthe fifth shaft 5 to the idler gear 13A of the first spur gear stageST1. Furthermore, the second shaft 2 is connectable through the fourthshifting element K4 designed as a clutch and through the ninth shaft 9to the idler gear 15 of the second spur gear stage ST2.

With the design variants in accordance with FIGS. 1 to 4 and 6, thefixed gear 12 of the first spur gear stage ST1 is connected through thesixth shaft 6 to the planetary gear carrier PT1 of the first planetarygear set RS1. In contrast to this, with the design variant in accordancewith FIG. 5, the idler gear 12A of the first spur gear stage ST1 isconnectable through the sixth shaft 6 and through the third shiftingelement K3 designed as a clutch and through the fifth shaft 5 to theplanetary gear carrier PT1 of the first planetary gear set RS1.

With the design variants in accordance with FIGS. 1 to 3 and 5 and 6,the fixed gear 14 of the second spur gear stage ST2 is connected throughthe seventh shaft 7 to the sun gear SR2 of the second planetary gear setRS2 and the ring gear HR3 of the third planetary gear set RS3. Incontrast to this, with the design variant in accordance with FIG. 4, thefixed gear 14 of the second spur gear stage ST2 is connected through theseventh shaft 7 to the ring gear HR3 of the third planetary gear setRS3. Furthermore, the fixed gear 14 of the second spur gear stage ST2and the ring gear HR3 of the third planetary gear set RS3 areconnectable through the third shifting element K3 designed as a clutchand through the fifth shaft 5 to the sun gear SR2 of the secondplanetary gear set RS2.

According to the design variants in accordance with FIGS. 1 and 3 to 6,the ring gear HR1 of the first planetary gear set RS1 is connectedthrough the eighth shaft 8 to the ring gear HR2 of the second planetarygear set RS2. In contrast to this, with the design variant in accordancewith FIG. 2, the ring gear HR1 of the first planetary gear set RS1 isconnectable through the fifth shaft 5 and the third shifting element K3designed as a clutch and through the eighth shaft 8 to the ring gear HR2of the second planetary gear set RS2.

FIG. 7 shows a shifting diagram or a shifting matrix, as the case maybe, for the equally effective transmission variants in accordance withFIGS. 1 to 6. In the shifting diagram, for the realization of thevarious gears, shifting elements K1, K2, K3, K4, B1, B2 to be locked oractivated, as the case may be, are shown in table form, whereas atransmission ratio i is indicated for each gear and the respective gearjump φ is indicated between different gears. In addition to the nineforward gears G1, G2, G3, G4, G5, G6, G7, G8, G9 and the specifiedreverse gear R, at least one additional shifting combination isindicated as alternative gear Z. As a whole, it also arises from theshifting diagram that the proposed multi-speed transmission featuresoptimized transmission ratio sequences with low absolute and relativerotational speeds and low torques for the planetary gear sets andshifting elements. In addition, good degrees of toothing efficiency andlow drag torques arise from the selected arrangements of the gear sets.

As preferred stationary transmission ratios, a value of approximatelyi₀=−2.388 can be used for the first planetary gear set RS1, a value ofapproximately i₀=−1.670 can be used for the second planetary gear setRS2, a value of approximately i₀=−3.850 can be used for the thirdplanetary gear set RS3. As the stationary transmission ratio, a value ofapproximately i_(ST1)=−1.000 is selected for the first spur gear stageST1, and a value of approximately i_(ST2)=−0.778 is selected for thesecond spur gear stage ST2. Moreover, it arises from the shiftingdiagram that, for shifting all gears G1, G2, G3, G4, G5, G6, G7, G8, G9,R, and Z, each of the three shifting elements is locked.

Specifically, it arises from the shifting diagram in accordance withFIG. 7 that, for the realization of the first forward gear G1, the firstshifting element K1 designed as a clutch, the third shifting element K3designed as a clutch and the fifth shifting element B1 designed as abrake are locked or activated. For the shifting of the second forwardgear G2, the third shifting element K3 designed as a clutch, the fifthshifting element B1 designed as a brake and the sixth shifting elementB2 designed as a brake are locked or activated. For the shifting of thethird forward gear G3, the third shifting element K3 designed as aclutch, the fourth shifting element K4 designed as a clutch and thefifth shifting element B1 designed as a brake are locked or activated.For the shifting of the fourth forward gear G4, the third shiftingelement K3 designed as a clutch, the fourth shifting element K4 designedas a clutch and the sixth shifting element B2 designed as a brake arelocked or activated. For the shifting of the fifth forward gear G5, thefirst shifting element K1 designed as a clutch, the third shiftingelement K3 designed as a clutch and the fourth shifting element K4designed as a clutch are locked or activated. For the shifting of thesixth forward gear G6, the second shifting element K2 designed as aclutch, the third shifting element K3 designed as a clutch and thefourth shifting element K4 designed as a clutch are locked or activated.For the shifting of the seventh forward gear G7, the first shiftingelement K1 designed as a clutch, the second shifting element K2 designedas a clutch and the third shifting element K3 designed as a clutch arelocked or activated. For the shifting of the eighth forward gear G8, thefirst shifting element K1 designed as a clutch, the second shiftingelement K2 designed as a clutch and the fourth shifting element K4designed as a clutch are locked or activated. For the shifting of theninth forward gear G9, the second shifting element K2 designed as aclutch, the fourth shifting element K4 designed as a clutch and thesixth shifting element B2 designed as a brake are locked or activated.Finally, for the shifting of the reverse gear R, the first shiftingelement K1 designed as a clutch, the fourth shifting element K4 designedas a clutch and the fifth shifting element B1 designed as a brake arelocked or activated.

With respect to the shifting combination of the alternative gear Z, itis provided that, for the shifting of the gear Z, the second shiftingelement clutch K2 designed as a clutch, the third shifting element K3designed as a clutch and the sixth shifting element B2 designed as abrake are locked or activated.

Modifications and variations can be made to the embodiments illustratedor described herein without departing from the scope and spirit of theinvention as set forth in the appended claims.

REFERENCE SIGNS

-   1 First shaft as a drive-   2 Second shaft as an output-   3 Third shaft-   4 Fourth shaft-   5 Fifth shaft-   6 Sixth shaft-   7 Seventh shaft-   8 Eighth shaft-   9 Ninth shaft-   11 Housing-   K1 First shifting element as a clutch-   K2 Second shifting element as a clutch-   K3 Third shifting element as a clutch-   K4 Fourth shifting element as a clutch-   B1 Fifth shifting element as a brake-   B2 Sixth shifting element as a brake-   RS1 First planetary gear set-   RS2 Second planetary gear set-   RS3 Third planetary gear set-   SR1 Sun gear of the first planetary gear set-   PT1 Planetary gear carrier of the first planetary gear set-   HR1 Ring gear of the first planetary gear set-   SR2 Sun gear of the second planetary gear set-   PT2 Planetary gear carrier of the second planetary gear set-   HR2 Ring gear of the second planetary gear set-   SR3 Sun gear of the third planetary gear set-   PT3 Planetary gear carrier of the third planetary gear set-   HR3 Ring gear of the third planetary gear set-   ST1 Machine element (first spur gear stage)-   ST2 Machine element (second spur gear stage)-   12 Fixed gear of the first spur gear stage-   12A Idler gear of the first spur gear stage-   13 Fixed gear of the first spur gear stage-   13A Idler gear of the first spur gear stage-   14 Fixed gear of the second spur gear stage-   15 Idler gear of the second spur gear stage-   G1 First forward gear-   G2 Second forward gear-   G3 Third forward gear-   G4 Fourth forward gear-   G5 Fifth forward gear-   G6 Sixth forward gear-   G7 Seventh forward gear-   G8 Eighth forward gear-   G9 Ninth forward gear-   R Reverse gear-   Z Alternative gear-   i Transmission ratio-   i₀ Stationary transmission ratios of the planetary gear sets-   I_(ST1) Stationary transmission ratio of the first spur gear stage-   I_(ST2) Stationary transmission ratio of the second spur gear stage-   φ Gear jump

The invention claimed is:
 1. A multi-speed transmission in planetarydesign for a vehicle, comprising: a housing (11); a first shaft (1)configured as a drive (An), and a second shaft (2) configured as anoutput (Ab) and arranged axially parallel to the drive; first, second,and third planetary gear sets (RS1, RS2, RS3); additional shafts (3, 4,5, 6, 7, 8, 9); six shifting elements (K1, K2, K3, K4, B1, B2) throughwhich actuation thereof results in a plurality of shiftable gears of thetransmission; machine elements (ST1, ST2) configured to transfer torquebetween the drive (An) and the output (Ab); the first shaft (1)connectable to a sun gear (SR3) of the third planetary gear set (RS3),to a planetary gear carrier (PT2) of the second planetary gear set(RS2), to a planetary gear carrier (PT3) of the third planetary gear set(RS3), and connectable or connected to a sun gear (SR1) of the firstplanetary gear set (RS1); the second shaft (2) connected or connectableto the first machine element (ST1) and to the second machine element(ST2); and wherein the first shaft (1) is connectable through a firstshifting element (K1) of the six shifting elements designed as a clutchand through a third shaft (3) of the additional shafts to the sun gear(SR3) of the third planetary gear set (RS3), and the sun gear (SR3) ofthe third planetary gear set (RS3) is connectable through the thirdshaft (3) and a sixth shifting element (B2) of the six shifting elementsdesigned as brake to the housing (11).
 2. The multi-speed transmissionaccording to claim 1, wherein the machine elements (ST1, ST2) are spurgear stages or chains.
 3. The multi-speed transmission according toclaim 1, wherein the first shaft (1) is connectable through a secondshifting element (K2) of the six shifting elements designed as a clutchand through a fourth shaft (4) of the additional shafts to the planetarygear carrier (PT2) of the second planetary gear set (RS2) and to theplanetary gear carrier (PT3) of the third planetary gear set (RS3). 4.The multi-speed transmission according to claim 1, wherein the firstshaft (1) Is connectable through a second shifting element (K2) of thesix shifting elements designed as a clutch, through a fourth shaft (4)of the additional shafts, through a third shifting element (K3) of thesix shifting elements designed as a clutch, and through a fifth shaft(5) of the additional shafts to the planetary gear carrier (PT2) of thesecond planetary gear set (RS2).
 5. The multi-speed transmissionaccording to claim 4, wherein the planetary gear carrier (PT3) of thethird planetary gear set (RS3) and the planetary gear carrier (PT2) ofthe second planetary gear set (RS2) are connectable through the fourthshaft (4) and through a fifth shifting element (B1) of the six shiftingelements designed as a brake to the housing (11).
 6. The multi-speedtransmission according to claim 1, wherein the first shaft (1) isconnectable through a third shifting element (K3) of the six shiftingelements designed as a clutch and through a fifth shaft (5) of theadditional shafts to the sun gear (SR1) of the first planetary gear set(RS1).
 7. The multi-speed transmission according to claim 1, wherein thefirst shaft (1) is connected to the sun gear (SR1) of the firstplanetary gear set (RS1).
 8. The multi-speed transmission according toclaim 1, wherein the machine elements are spur gear stages (ST1, ST2),and the second shaft (2) is connected to a fixed gear (13) of a firstspur gear stage (ST1) of the machine elements and the second shaft (2)is connectable through a fourth shifting element (K4) of the sixshifting elements designed as a clutch and through a ninth shaft (9) ofthe additional shafts to an idler gear (15) of a second spur gear stage(ST2).
 9. The multi-speed transmission according to claim 1, wherein themachine elements are spur gear stages (ST1, ST2), and the second shaft(2) is connectable through a third shifting element (K3) of the sixshifting elements designed as a clutch and through a fifth shaft (5) ofthe additional shafts to an idler gear (13A) of a first spur gear stage(ST1) of the machine elements, and the second shaft (2) is connectablethrough a fourth shifting element (K4) of the six shifting elementsdesigned as a clutch and through a ninth shaft (9) of the additionalshafts to an idler gear (15) of a second spur gear stage (ST2) of themachine elements.
 10. The multi-speed transmission according to claim 1,wherein the machine elements are spur gear stages (ST1, ST2), and afixed gear (12) of a first spur gear stage (ST1) of the machine elementsis connected through a sixth shaft (6) of the additional shafts to aplanetary gear carrier (PT1) of the first planetary gear set (RS1). 11.The multi-speed transmission according to claim 1, wherein the machineelements are spur gear stages (ST1, ST2), and an idler gear (12A) of afirst spur gear stage (ST1) of the machine elements is connectablethrough a sixth shaft (6) of the additional shafts, through a thirdshifting element (K3) of the six shifting elements designed as a clutch,and through a fifth shaft (5) of the additional shafts to a planetarygear carrier (PT1) of the first planetary gear set (RS1).
 12. Themulti-speed transmission according to claim 1, wherein the machineelements are spur gear stages (ST1, ST2), and a fixed gear (14) of asecond spur gear stage (ST2) of the machine elements is connectedthrough a seventh shaft (7) of the additional shafts to a sun gear (SR2)of the second planetary gear set (RS2) and a ring gear (HR3) of thethird planetary gear set (RS3).
 13. The multi-speed transmissionaccording to claim 1, wherein the machine elements are spur gear stages(ST1, ST2), and a fixed gear (14) of a second spur gear stage (ST2) ofthe machine elements is connected through a seventh shaft (7) of theadditional shafts to a ring gear (HR3) of the third planetary gear set(RS3), and that the fixed gear (14) of the second spur gear stage (ST2)and the ring gear (HR3) of the third planetary gear set (RS3) areconnectable through a third shifting element (K3) of the six shiftingelements designed as a clutch and through a fifth shaft (5) of theadditional shafts to a sun gear (SR2) of the second planetary gear set(RS2).
 14. The multi-speed transmission according to claim 1, wherein aring gear (HR1) of the first planetary gear set (RS1) is connectedthrough an eighth shaft (8) of the additional shafts to a ring gear(HR2) of the second planetary gear set (RS2).
 15. The multi-speedtransmission according to claim 1, wherein a ring gear (HR1) of thefirst planetary gear set (RS1) is connectable through a fifth shaft (5)of the additional shafts, a third shifting element (K3) of the sixshifting elements designed as a clutch, and through the eighth shaft (8)to a ring gear (HR2) of the second planetary gear set (RS2).
 16. Themulti-speed transmission according to claim 1, wherein the plurality ofshiftable gears comprise at least nine forward gears (G1 to G9) and atleast one reverse gear (R).
 17. The multi-speed transmission accordingto claim 16, wherein the shifting elements (K1, K2, K3, K4, B1, B2) arefrictional-locking or positive-locking shifting elements.
 18. Themulti-speed transmission according to claim 16, wherein: for shifting ofa first forward gear (G1) of the at least nine forward gears, the firstshifting element (K1) of the six shifting elements designed as a clutch,a third shifting element (K3) of the six shifting elements designed as aclutch, and a fifth shifting element (B1) of the six shifting elementsdesigned as a brake are locked; for shifting of a second forward gear(G2) of the at least nine forward gears, the third shifting element (K3)designed as a clutch, the fifth shifting element (B1) designed as abrake, and a sixth shifting element (B2) of the six shifting elementsdesigned as a brake are locked; for shifting of a third forward gear(G3) of the at least nine forward gears, the third shifting element (K3)designed as a clutch, a fourth shifting element (K4) of the six shiftingelements designed as a clutch, and the fifth shifting element (B1)designed as a brake are locked; for shifting of a fourth forward gear(G4) of the at least nine forward gears, the third shifting element (K3)designed as a clutch, the fourth shifting element (K4) designed as aclutch, and the sixth shifting element (B2) designed as a brake arelocked; for shifting of a fifth forward gear (G5) of the at least nineforward gears, the first shifting element (K1) designed as a clutch, thethird shifting element (K3) designed as a clutch, and the fourthshifting element (K4) designed as a clutch are locked; for shifting of asixth forward gear (G6) of the at least nine forward gears, a secondshifting element (K2) of the six shifting elements designed as a clutch,the third shifting element (K3) designed as a clutch, and the fourthshifting element (K4) designed as a clutch are locked; for shifting of aseventh forward gear (G7) of the at least nine forward gears, the firstshifting element (K1) designed as a clutch, the second shifting element(K2) designed as a clutch, and the third shifting element (K3) designedas a clutch are locked; for shifting of an eighth forward gear (G8) ofthe at least nine forward gears, the first shifting element (K1)designed as a clutch, the second shifting element (K2) designed as aclutch, and the fourth shifting element (K4) designed as a clutch arelocked; for shifting of a ninth forward gear (G9) of the at least nineforward gears, the second shifting element (K2) designed as a clutch,the fourth shifting element (K4) designed as a clutch, and the sixthshifting element (B2) designed as a brake are locked; and for shiftingof a reverse gear (R) of the at least one reverse gear, the firstshifting element (K1) designed as a clutch, the fourth shifting element(K4) designed as a clutch, and the fifth shifting element (B1) designedas a brake are locked.
 19. The multi-speed transmission according toclaim 18, wherein for shifting of an alternative gear (Z), the secondshifting element (K2) designed as a clutch, the third shifting element(K3) designed as a clutch, and the sixth shifting element (B2) designedas a brake are locked.